Mitsubishi Electric FR-A820-00046 (0.4K), Instruction Manual

Page: 451 / 1218

Parameters (F) Setting of acceleration/deceleration time and acceleration/deceleration pattern
FR-A800 5 - 249
S-pattern acceleration/deceleration A (Pr. 29 = "1")
●
Use this when acceleration/deceleration is required for a short time until a high-speed area equal
to or higher than the base frequency, such as for the main shaft of the machine.
●
The acceleration/deceleration pattern has the Pr. 3 "Base frequency" (Pr. 84 "Rated motor frequen-
cy" under PM sensorless vector control) (fb) as the point of inflection in an S-pattern curve, and
the acceleration/deceleration time can be set to be suitable for the motor torque reduction in the
constant-power operation range at the base frequency (fb) or more.
●
Acceleration/deceleration time calculation method when the set frequency is equal to or higher
than the base frequency
Acceleration time t = (4/9) × (T/fb²) × f² + (5/9) × T
T: acceleration/deceleration time (s)
f: set frequency (Hz)
fb: base frequency (rated motor frequency)
●
Reference (0 Hz to set frequency) of acceleration/deceleration time when Pr. 3 = "60 Hz"
S-pattern acceleration/deceleration B (Pr. 29 = "2")
●
This is useful for preventing collapsing stacks such as on a conveyor. S-pattern acceleration/
deceleration B can reduce the impact during acceleration/deceleration by accelerating/deceler-
ating while maintaining an S-pattern from the present frequency (f2) to the target frequency (f1).
Fig. 5-91:
Characteristic for parameter 29 = 1
I002557E_B
Acceleration/deceleration time (s)
Set frequency (Hz)
60 120 200 400
5 5 12 27 102
15 15 35 82 305
Tab. 5-97: Acceleration/deceleration times when Pr. 3 = 60 Hz
NOTE For the acceleration/deceleration time setting of the S-pattern acceleration/deceleration A, set the
time to Pr. 3 (Pr. 84 under PM sensorless vector control) instead of Pr. 20 "Acceleration/decelera-
tion reference frequency".
Fig. 5-92:
Characteristic for parameter 29 = 2
I002558E_B
fb
[S-pattern acceleration/
deceleration A]
Time
Output fr
equenc
y
(H
z)
f1
f2
[S-pattern acceleration/
deceleration B]
Out
p
u
t fr
equen
cy
(Hz)
S
et fr
e
q
uenc
y
(Hz)
Time